Early Study Using Roundworms Finds Probiotic Protective Against Parkinson Disease

A new study published in Cell Reports found a common gut bacterium that boosts digestive health may also help guard against Parkinson disease (PD).

The probiotic Bacillus subtilis strain PXN21 can slow and even reverse build-up of the protein α-synuclein, which is associated with PD. In the brains of patients with PD, α-synuclein “misfolds and builds up, forming toxic clumps. These clumps are associated with the death of nerve cells responsible for producing dopamine. The loss of these cells causes the motor symptoms associated with Parkinson's, including freezing, tremors, and slowness of movement,” according to the study's researchers.

The study was conducted on roundworms altered to produce the human version of α-synuclein. Bacillus subtilis, when introduced in the roundworms, was effective in protecting against build-up of the harmful α-synuclein protein and was able to clear formed protein clumps. As a result, movement symptoms associated with PD improved in the roundworms. The researchers also found, “The bacteria was able to prevent the formation of toxic α-synuclein clumps by producing chemicals that change how enzymes in cells process specific fats called sphingolipids.”

The encouraging outcomes prompted the researchers to suggest the next steps of confirming results in mice, followed by clinical trials. They say the probiotic is already commercially available, which means clinical trials can be fast-tracked.

Previous studies have documented how fecal transplants from patients with PD to mouse models exacerbated symptoms of PD, suggesting differences in microbiota can impact the disease’s progression and are not merely a result of PD, as well as shown that PD symptoms and α-synuclein pathology begin in peripheral tissues, specifically the intestine, and that as the disease progresses, the protein aggregates spread to brain regions.

“Preclinical evidence suggests that the gut microbiota and intestinal permeability modulate behavior, mood, and neuropsychiatric disorders,” researchers have noted.

PD is one of the most prevalent neurodegenerative disorders in the world, and currently there is no cure. The research manager at Parkinson’s UK, Beckie Port, PhD, said of the results, “Studies that identify bacteria that are beneficial in Parkinson's have the potential to not only improve symptoms but could even protect people from developing the condition in the first place.” Parkinson’s UK funded the Cell Reports study.

Reference

Goya ME, Xue F, Sampedro-Torres-Quevedo C, et al. Probiotic Bacillus Subtilis protects against a-synuclein aggregation in C. Elegans. Cell Rep. 2020;30(2):367-380. doi: 10.1016/j.celrep.2019.12.078.